Centrifugal separator

ABSTRACT

The housing of a centrifugal separator is comprised of an upper portion elastically supported on a fixed lower portion. The upper portion carries the separator bowl as well as the feed and discharge assemblies of the separator, and the entire weight of the upper housing portion and the parts it carries is elastically supported at the level of the center of gravity of this weight.

United States Patent [151 3, 3

Mercier [4 1 Aug. 8, 1972 CENTRIFUGAL SEPARATOR 2,019,827 11/1935Odajima ..233/1 X Inventor: Rue y Lussac, L618 La Madelaine France l3,050,190 8/1962 Slepe ..233/380 [22] F1led: Dec. 8, 1969 3,081,0263/1963 Lacker et a1 ..233/2 [21] Appl 882 879 3,437,209 4/1969 Evans..233/2 X Primary Examiner-Jordan Franklin [30] Foreign ApplicationPriority Data Assistant Examiner-George H. Krizmanich Dec. 9, 1968France ..68177148 Wm-Km Kelma 57 ABSTRACT [52] US. Cl ..233/1 C, 233/2,233/26 1 51 1111. C1. ..B01d 21/26, B04b 9/12, B04b 3/00 The housmg 9 acempfugal separator 18 comp/used of [58] Field of Search ..233/1 R, 1 c,2, 3, 21, 16, ap r elastlfglly f z on f g? 233 2 27; 210 4 p0 011. eupper p0 011 carnes C separa 01' OW I I3 80 83 as well as the feed anddischarge assemblies of the separator, and the entire weight of theupper housing [56] References cued portion and the parts it carries iselastically supported rr STATES PATENTS at the level of the center ofgravity of this weight.

1,242,866 1917 Riggs ..233/27 9 Claims, 3 Drawing Figures 4 I 32 50 I l54 52 I9 I4 22 34 s 42 I 0 12 as 23 [Ill 37 5 44 I. 26

I I 27 28 2 4o 2o 24 1 t 1 1 i 1 f PATENTEDAus 8 m2 SHEET 1 OF 2INVENTOR. ANDRE MERCIER AGENT CENTRIFUGAL SEPARATOR The presentinvention relates to improvements in centrifugal separators forseparating a solid-liquid mixture in a separator bowl rotating about avertical axis.

In separators of this type, the bowl rotates at considerable speed,which often produces vibrations even if the weight of the machine partsis in proper equilibrium. Such vibrations may be caused, for instance,by non-uniform distribution of the material on the filter screen mountedon the separator bowl, particularly if such material is highly viscousand/or if the screen becomes partly displaced in the bowl.

lmbalances are generally found at the geometric center of gravity of theinterior surface of the bowl. While elastic supports have been proposedin centrifugal separators between the rotating and fixed parts of themachine or between the machine and the foundation on which it rests, theforces of imbalance in the conventional separators are in a plane abovethe center of gravity of the elastically suspended or supported mass,thus producing vibrations which are transmitted to the foundation onwhich the machine rests, despite the elastic support means.

It is the primary object of this invention to overcome this disadvantageby so assembling the elastically supported parts of the machine that thecenter of gravity of the suspended parts, approaches as closely aspossible the geometrical center of gravity of the interior surface ofthe separator bowl, and to suspend the parts elastically at that level,while at the same time assuring a more uniform distribution of thematerial to be separated in the separator bowl, thus reducing the forcesof imbalance during the separating operation.

This and other objects of the invention are accomplished in acentrifugal separator which comprises a housing including an upperportion, a fixedly supported lower portion, and an elastic support meansresiliently supporting the upper housing portion of the separator on thelower separator housing portion. A vertically extending pivot in thehousing is supported by the upper separator housing portion. Aseparating bowl having a hub is mounted for rotation on and about thepivot, the pivot extending into the interior of the bowl. The upperseparator housing portion and all elements carried thereby, includingthe pivot and the bowl, have a center of gravity, and the elasticsupport means is positioned approximately at the level of the center ofgravity. A screen is mounted over the interior surface of the bowl andspaced therefrom, the bowl and the screen being frusto-conical, and theelastic support means is positioned approximately at the level of thegeometric center of gravity of the interior surface of the frustoconicalbowl, in the embodiment of the invention described and illustratedherein.

Due to this construction and distribution of weight and forces, theelastically suspended or supported part of the separator is subjectedpractically only to horizontal vibrations. If the elasticcharacteristics of the suspension means, such as rubber blocks or arubber ring interposed between the upper and lower separator housingportions, are proper chosen, the machine may be insulated fromvibrations, the vibrations of the elastic suspension means beingopposite in phase to the forces of imbalance.

To bring the center of gravity of the suspended machine partsapproximately to the level of the geometrical center of gravity of theinterior surface of the bowl, it may be necessary to make the upperportions of the upper housing portion somewhat heavier. This may beeffected by increasing the thickness of the upper wall portion of theupper housing portion and/or by attaching an additional mass thereto.

The more even distribution of the material charged into the separatorbowl is assured with a feed assembly which includes a feed pipe havingan outlet end, the feed pipe being supported on the housing cover, aconical element fixed to the top of the bowl hub, the outlet end of thefeed pipe being in registry with the conical element to deliver thematerial to this element, and a turbine wheel having radially extendingblades fixed to the conical element. The blades define spacestherebetween concentrically surrounding the conical element andreceiving the material from the conical element, and an outwardlyflaring tube is fixed to the turbine wheel and surrounds the hub. Anannular chamber is defined between the tube and hub for receiving thematerial from the spaces between the turbine wheel blades, the lower endof the tube defines with the bottom of the bowl a circular deliveryopening means for delivering the material to the bowl, and the upper endof the tube surrounds the outlet end of the feed pipe.

A tight joint is provided between the upper tube end and the feed pipeoutlet end to prevent the turbine wheel from acting like a ventilatorand producing significant air circulation in the interior of the bowl.

The above and other objects, advantages and features of the presentinvention will become more apparent in the following detaileddescription of certain preferred embodiments thereof, taken inconjunction with the accompanying drawing wherein FIG. 1 is a side view,largely in section, of a centrifugal separator according to thisinvention;

FIG. 2 is a side view of a small portion of the separator showing amodified suspension means; and

FIG. 3 is an enlarged sectional view showing modified feed assembly forthe separator.

Referring now to the drawing and first to FIG. 1, there is shown acentrifugal separator comprising a frusto-conical or funnel-shaped bowlor basket 10 having an imperforate wall. A similarly funnel-shapedscreen or sieve 12 is mounted in the bowl l0 spaced from the bowl wallso that an annular space is defined between the bowl wall and the screenfor receiving liquid filtered through the screen during operation of theseparator. This liquid is upwardly displaced during rotation of the bowltowards discharge lip 10a of the bowl. A frusto-conical skirt 14 havingan imperforate wall is mounted on the discharge lip of the bowl so as toreceive liquid passed outwardly through a series of apertures or anannular slot on the circumference of the discharge lip, the dischargeliquid running downwardly on the skirt 14 into annular reservoir 16constituted by sleeve 18 surrounding the bowl 10.

The upper rim of sleeve 18 extends close to the discharge lip of theseparator bowl and a bottom wall 20 closes off the reservoir 16 whenceliquid is discharged through pipe 31 passing outwardly through the wallsof hopper 29. The sleeve 18 is fixed by brackets or braces 19, to thefixed upper portion of the separator housing, and brackets or braces 21to annular support 37.

The upper portion of the separator housing is constituted by athick-walled top cylinder 22 and downwardly extending thin-walled skirt24 overlapping the cylindrical lower portion 28 of the separatorhousing. As shown, a base 33 extends radially outwardly from the lowerportion of the separator housing to mount the lower separator housingportion rigidly on the foundation 29 which supports the separator. Thesolid material separated from the liquid in the centrifugal separator isdischarged through hopper 29 which extends downwardly from the separatorhousing and is flanged to the lower end of the lower separator housingportlon.

The upper separator housing portion is resiliently mounted on the lowerseparator housing portion in the following manner:

Support frameworks 27 are fixedly mounted on, or are integral with, thewall of the lower separator housing portion 28 and/or the base 33, andthese supports 27 carry elastic or resilient blocks 26, for instance ofrubber, which support the upper separator housing portion, brackets 23extending radially outwardly from the thick-walled top cylinder 22 torest on the resilient blocks 26. These blocks are positioned at thelevel of the center of gravity G of the suspended upper portion of theseparator.

The interior of the separator housing is sealed from the atmosphere bymeans of suitable sealing means, such as an annular gasket 30 or abellows sealing the joint between the upper and lower portions of thehousing.

The bowl rotates about the vertical pivot 34 whose axial bore houses thedrive shaft 44. An annular rim 35 reinforced by radical ribs 39 extendsfrom the lower or interior end of the pivot 34 into engagement with anannular support flange 36 which extends radially inwardly from sleeve37. The pivot extends from its lower end outside the bowl 10 into thebowl where it carries the hub 38 on anti-friction bearings 40 and 42,the bowl 10 being fixedly connected to the hub 38.

The hub 38 is bolted or otherwise fixed to the upper end of the driveshaft 44 whose lower end carries drive pulley 43 connected by belt 41 topulley 45 of motor 46, which is mounted onv base 33 and drives shaft 44and bowl 10.

As more clearly shown in the enlarged view of FIG. 3, a conical element48 is fixed to the top of hub 38 in registry with the outlet of a feedconduit 50 mounted on the cover 32 of the separator housing. The conicalelement 48 forms the hub of a turbine wheel 52 whose radially extendingblades carry an outwardly flaring tube 54 whose upper rim surrounds theoutlet opening or nozzle of pipe 50. The tube extends towards the bottomof the separator bowl l0, defining with hub 38 an annular feed chamber56, a circular discharge slot being formed between the lower rim of thetube 54 and the bottom of the separator bowl.

As will be apparent from the above description, the resilientlysuspended upper portion of the centrifugal separator consists of thecylindrical housing portion 22, 24, the cover 32, which is supported onthe thickwalled cylinder 22, and the feed pipe means carried by thecover, the support elements for the pivot 34, which includes the sleeve18, the brackets or braces 19, 21 mounting the sleeve on the housingwall 22, 24 and the sleeve 37, with the support flange 36, the driveshaft 44, the bowl 10 and its hub 38, and the screen 12. In thisstructure, wherein the lower portion of the separator is fixed and thevertical pivot about which the bowl rotates extends into the bowl, thecenter of gravity G of the suspended mass of the separator isconsiderably higher than in conventional apparatus of this type. Thethickness of the upper wall portion 22 of the separator housing is sochosen or additional material is attached thereto so that the center ofgravity of the entire suspended mass is about at the same level as thegeometric center of gravity of the interior surface of the bowl. Sincethe forces of imbalance due to a nonuniform distribution of the chargein the bowl are generally situated at this level, no tilting moment isexerted upon the suspended portion of the separator and the vibratorymovements are solely horizontal.

Furthermore, the axis of rotation of the bowl is displaced parallel toitself during such vibrations, so that no tilting movement would appearunless the pivot 34 were bent. Since the latter is rigid, however, anysuch tilt would at most be very slight.

The suspension blocks 26, which are positioned at A the level of thecenter of gravity of the suspended mass,

are subject only to vibrations in this plane. The elasticity andabsorption or damping characteristics of these support blocks are sochosen as to provide an insulation against vibration.

FIG. 2 shows a modified suspension means in which the elastic suspensionblocks are replaced by a rubber ring of suitable elasticity and dampingcharacteristics. In this modification, the thick-walled cylinder wall 22of the upper portion of the separator housing and the cylinder wall 28'of the lower separator housing portion have facing annular rims 22a and28a, respectively, which define mating grooves receiving the rubber ring60. In this way, the suspension ring 60 simultaneously serves as asealing means or gasket for the joint of the separator housing portions.

The centrifugal separator hereinabove described and herein illustratedoperates as follows:

A liquid-solid mixture is charged into bowl 10 through the feed pipe 50,passing outwardly between the blades of the turbine wheel 52 through theopening between the outlet end of the pipe 50 and the conical hub of theturbine wheel. Since the conical hub 48 is fixed on, or integral with,the hub 38 of the bowl 10, it turns at high speed with the bowl when themotor 46 is actuated to drive shaft 44. The liquid-solid mixture chargedinto the separator through pipe 50 is thus entrained by friction andbegins to rotate with the conical element 48. Under centrifugal force,the charge will leave the feed pipe in a horizontal layer and will bedistributed at the speed of rotation of the bowl. The turbine blades arehelically inclined so as to direct the charged mixture downwardly intothe tube 54 where it passes through chamber 56 and outwardly into thebowl through the circular slot defined between the lower rim of the tube54 and the bottom of the bowl. The conical element 48 and the turbinewheel blades divide the jet of material entering the separator intoseveral layers, which is essential for a uniform distribution of thematerial in the tube 54 under centrifugal action in case the material isvery viscous. The material forms a continuous layer of uniform thicknesson the wall of tube 54 under centrifugal force, and this layer ofmaterial is discharged at the bottom of the tube and is thrown againstthe screen 12 where it is upwardly displaced by the centrifugal force.The liquid phase of the mixture is filtered through the screen and movesupwardly in the annular chamber between the screen and the imperforatewall of the bowl to be discharged through lip a into the reservoir 16.The solid phase of the mixture is equally displaced upwardly on thescreen 12, finally passing over the upper edge of the screen into theseparator housing where it is discharged by gravity into hopper 29.

The specific feed system herein described permits a particularly uniformdistribution of the charged material over the whole surface of thescreen, thus reducing vibrations due to forces of imbalance.

In the modification of the feed system shown in FIG. 3, the feed pipe50' does not have an inwardly flaring outlet nozzle, as illustrated inFIG. 1, but the diameter of the feed pipe is greater than that of thematerial being fed so that the same freely falls onto the conicalelement 48. The feed pipe 50 is mounted on the tube 54 by a jointconstituted by a pair of horizontal flanges 62 and 64 respectively fixedto the pipe 50' and the tube 54. The vertical position of the feedpipeis adjustable by wedge 66 positioned between the housing cover 32 and aflange 65 on the feed pipe to maintain a small gap between the flanges62 and 64. This gap and the thickness of the flanges are so chosen as toavoid too strong an air circulation in the interior of the bowl becauseof the suction produced by the turbine wheel 52 which operates like aventilator. This joint may be replaced by a labyrinth joint or any othersuitable joint of conventional design serving the same purpose.

It should also be noted that, while the invention has been illustratedin connection with a frusto-conical bowl with an imperforate wall, it isobviously applicable to centrifugal separators with perforated basketsand with cylindrical rotating bowls. Other modifications may readilyoccur to those skilled in the art without departing from the spirit andscope of the present invention.

I claim:

1. A centrifugal separator comprising 1. a housing, the housingincluding a. an upper portion,

b. a fixedly supported lower portion, and

c. an elastic support means resiliently supporting the upper housingportion of the separator on the lower separator housing portion; 2. avertically extending pivot in said housing,

d. the pivot being carried by the upper separator housing portion; and3. a separating bowl having a hub mounted for rotation on and about saidpivot and carried thereby;

e. the pivot extending into the interior of the bowl,

f. the upper separator housing portion and all elements carried thereby,including the pivot and the bowl, having a center of gravity, and

g. the elastic support means being positioned approximately at the levelof the center of gravity.

2. The centrifugal separator of claim 1, further including a screenmounted over the interior surface of the bowl and spaced therefrom.

3. The centrifugal separator of claim 2, wherein the bowl and the screenare frgsto-conical, afld th el sti support means is posrtroneapproxlmate y at t e eve of the geometric center of gravity of theinterior surface of the frusto-conical bowl.

4. The centrifugal separator of claim 1, further comprising a cover onthe housing and a feed assembly for delivering material to be separatedto the bowl, the feed assembly including a feed pipe having an outletend, the feed pipe being supported on the housing cover, a conicalelement fixed to the top of the bowl hub, the outlet end of the feedpipe being in registry with the conical element to deliver the materialto said element, a turbine wheel having radially extending blades fixedto the conical element, the blades defining spaces therebetweenconcentrically surrounding the conical element and receiving thematerial from the conical element, an outwardly flaring tube fixed tothe turbine wheel and surrounding the hub, an annular chamber beingdefined between the tube and the hub for receiving the material fromsaid spaces, the lower end of the tube defining with the bottom of thebowl a circular delivery opening means for delivering the material tothe bowl, and the upper end of the tube surrounding the outlet end ofthe feed pipe.

5. The centrifugal separator of claim 4, further comprising a jointbetween the upper end of the tube and the outlet end of the feed pipe.

6. The centrifugal separator of claim 1, wherein the upper housingportion comprises an upper and a lower wall portion, the thickness ofthe upper wall portion exceeding that of the lower wall portion.

7. The centrifugal separator of claim 1, wherein the elastic supportmeans comprises blocks of elastic material.

8. The centrifugal separator of claim 1, wherein the elastic supportmeans comprises a ring of elastic material mounted between the upper andlower separator housing portions.

9. The centrifugal separator of claim 1, further comprising a tightjoint between the upper and lower separator housing portions.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. 3,682,373 Dated At gust s, 1972 Inventor(s) Andre Mercier It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In Col. 1, after item (72) insert=-- (73) Assignee: Fives Lille-Gail,Paris, France Signed and sealed this 13th day of-March 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM Po-105O (10-69) USCOMM-DC man-ps9 U,$. GOVERNMENTPRINTING OFFICE: 1969 O--366-33 L

1. A centrifugal separator comprising
 1. a housing, the housingincluding a. an upper portion, b. a fixedly supported lower portion, andc. an elastic support means resiliently supporting the upper housingportion of the separator on the lower separator housing portion;
 2. avertically extending pivot in said housing, d. the pivot being carriedby the upper separator housing portion; and
 3. a separating bowl havinga hub mounted for rotation on and about said pivot and carried thereby;e. the pivot extending into the interior of the bowl, f. the upperseparator housing portion and all elements carried thereby, includingthe pivot and the bowl, having a center of gravity, and g. the elasticsupport means being positioned approximately at the level of the centerof gravity.
 2. a vertically extending pivot in said housing, d. thepivot being carried by the upper separator housing portion; and
 2. Thecentrifugal separator of claim 1, further including a screen mountedover the interior surface of the bowl and spaced therefrom.
 3. Thecentrifugal separator of claim 2, wherein the bowl and the screen arefrusto-conical, and the elastic support means is positionedapproximately at the level of the geometric center of gravity of theinterior surface of the frusto-conical bowl.
 3. a separating bowl havinga hub mounted for rotation on and about said pivot and carried thereby;e. the pivot extending into the interior of the bowl, f. the upperseparator housing portion and all elements carried thereby, includingthe pivot and the bowl, having a center of gravity, and g. the elasticsupport means being positioned approximately at the level of the centerof gravity.
 4. The centrifugal separator of claim 1, further comprisinga cover on the housing and a feed assembly for delivering material to beseparated to the bowl, the feed assembly including a feed pipe having anoutlet end, the feed pipe being supported on the housing cover, aconical element fixed to the top of the bowl hub, the outlet end of thefeed pipe being in registry with the conical element to deliver thematerial to said element, a turbine wheel having radially extendingblades fixed to the conical element, the blades defining spacestherebetween concentrically surrounding the conical element andreceiving the material from the conical element, an outwardly flaringtube fixed to the turbine wheel and surrounding the hub, an annularchamber being defined between the tube and the hub for receiving thematerial from said spaces, the lower end of the tube defining with thebottom of the bowl a circular delivery opening means for delivering thematerial to the bowl, and the upper end of the tube surrounding theoutlet end of the feed pipe.
 5. The centrifugal separator of claim 4,further comprising a joint between the upper end of the tube and theoutlet end of the feed pipe.
 6. The centrifugal separator of claim 1,wherein the upper housing portion comprises an upper and a lower wallportion, the thickness of the upper wall portion exceeding that of thelower wall portion.
 7. The centrifugal separator of claim 1, wherein theelastic support means comprises blocks of elastic material.
 8. Thecentrifugal separator of claim 1, wherein the elastic support meanscomprises a ring of elastic material mounted between the upper and lowerseparator housing portions.
 9. The centrifugal separator of claim 1,further comprising a tight joint between the upper and lower separatorhousing portions.